"""
Slider
======
.. image:: images/slider.jpg
The :class:`Slider` widget looks like a scrollbar. It supports horizontal and
vertical orientations, min/max values and a default value.
To create a slider from -100 to 100 starting from 25::
from kivy.uix.slider import Slider
s = Slider(min=-100, max=100, value=25)
To create a vertical slider::
from kivy.uix.slider import Slider
s = Slider(orientation='vertical')
"""
__all__ = ('Slider', )
from kivy.uix.widget import Widget
from kivy.properties import (NumericProperty, AliasProperty, OptionProperty,
ReferenceListProperty, BoundedNumericProperty)
[docs]class Slider(Widget):
"""Class for creating a Slider widget.
Check module documentation for more details.
"""
value = NumericProperty(0.)
'''Current value used for the slider.
:attr:`value` is a :class:`~kivy.properties.NumericProperty` and defaults
to 0.'''
min = NumericProperty(0.)
'''Minimum value allowed for :attr:`value`.
:attr:`min` is a :class:`~kivy.properties.NumericProperty` and defaults to
0.'''
max = NumericProperty(100.)
'''Maximum value allowed for :attr:`value`.
:attr:`max` is a :class:`~kivy.properties.NumericProperty` and defaults to
100.'''
padding = NumericProperty(10)
'''Padding of the slider. The padding is used for graphical representation
and interaction. It prevents the cursor from going out of the bounds of the
slider bounding box.
By default, padding is 10. The range of the slider is reduced from padding
\*2 on the screen. It allows drawing a cursor of 20px width without having
the cursor go out of the widget.
:attr:`padding` is a :class:`~kivy.properties.NumericProperty` and defaults
to 10.'''
orientation = OptionProperty('horizontal', options=(
'vertical', 'horizontal'))
'''Orientation of the slider.
:attr:`orientation` is an :class:`~kivy.properties.OptionProperty` and
defaults to 'horizontal'. Can take a value of 'vertical' or 'horizontal'.
'''
range = ReferenceListProperty(min, max)
'''Range of the slider in the format (minimum value, maximum value)::
>>> slider = Slider(min=10, max=80)
>>> slider.range
[10, 80]
>>> slider.range = (20, 100)
>>> slider.min
20
>>> slider.max
100
:attr:`range` is a :class:`~kivy.properties.ReferenceListProperty` of
(:attr:`min`, :attr:`max`).
'''
step = BoundedNumericProperty(0, min=0)
'''Step size of the slider.
.. versionadded:: 1.4.0
Determines the size of each interval or step the slider takes between
min and max. If the value range can't be evenly divisible by step the
last step will be capped by slider.max
:attr:`step` is a :class:`~kivy.properties.NumericProperty` and defaults
to 1.'''
def get_norm_value(self):
vmin = self.min
d = self.max - vmin
if d == 0:
return 0
return (self.value - vmin) / float(d)
def set_norm_value(self, value):
vmin = self.min
step = self.step
val = value * (self.max - vmin) + vmin
if step == 0:
self.value = val
else:
self.value = min(round((val - vmin) / step) * step + vmin,
self.max)
value_normalized = AliasProperty(get_norm_value, set_norm_value,
bind=('value', 'min', 'max', 'step'))
'''Normalized value inside the :attr:`range` (min/max) to 0-1 range::
>>> slider = Slider(value=50, min=0, max=100)
>>> slider.value
50
>>> slider.value_normalized
0.5
>>> slider.value = 0
>>> slider.value_normalized
0
>>> slider.value = 100
>>> slider.value_normalized
1
You can also use it for setting the real value without knowing the minimum
and maximum::
>>> slider = Slider(min=0, max=200)
>>> slider.value_normalized = .5
>>> slider.value
100
>>> slider.value_normalized = 1.
>>> slider.value
200
:attr:`value_normalized` is an :class:`~kivy.properties.AliasProperty`.
'''
def get_value_pos(self):
padding = self.padding
x = self.x
y = self.y
nval = self.value_normalized
if self.orientation == 'horizontal':
return (x + padding + nval * (self.width - 2 * padding), y)
else:
return (x, y + padding + nval * (self.height - 2 * padding))
def set_value_pos(self, pos):
padding = self.padding
x = min(self.right - padding, max(pos[0], self.x + padding))
y = min(self.top - padding, max(pos[1], self.y + padding))
if self.orientation == 'horizontal':
if self.width == 0:
self.value_normalized = 0
else:
self.value_normalized = (x - self.x - padding
) / float(self.width - 2 * padding)
else:
if self.height == 0:
self.value_normalized = 0
else:
self.value_normalized = (y - self.y - padding
) / float(self.height - 2 * padding)
value_pos = AliasProperty(get_value_pos, set_value_pos,
bind=('x', 'y', 'width', 'height', 'min',
'max', 'value_normalized', 'orientation'))
'''Position of the internal cursor, based on the normalized value.
:attr:`value_pos` is an :class:`~kivy.properties.AliasProperty`.
'''
def on_touch_down(self, touch):
if self.disabled or not self.collide_point(*touch.pos):
return
if touch.is_mouse_scrolling:
if 'down' in touch.button or 'left' in touch.button:
if self.step:
self.value = min(self.max, self.value + self.step)
else:
self.value = min(
self.max,
self.value + (self.max - self.min) / 20)
if 'up' in touch.button or 'right' in touch.button:
if self.step:
self.value = max(self.min, self.value - self.step)
else:
self.value = max(
self.min,
self.value - (self.max - self.min) / 20)
else:
touch.grab(self)
self.value_pos = touch.pos
return True
def on_touch_move(self, touch):
if touch.grab_current == self:
self.value_pos = touch.pos
return True
def on_touch_up(self, touch):
if touch.grab_current == self:
self.value_pos = touch.pos
return True
if __name__ == '__main__':
from kivy.app import App
class SliderApp(App):
def build(self):
return Slider(padding=25)
SliderApp().run()